glTexSubImage2D(3G)
glTexSubImage2D - specify a two-dimensional texture subimage
As shipped in IRIX 6.5.30. Last changed in IRIX 6.5.15.
NAME glTexSubImage2D - specify a two-dimensional texture subimage C SPECIFICATION void glTexSubImage2D( GLenum target, GLint level, GLint xoffset, GLint yoffset, GLsizei width, GLsizei height, GLenum format, GLenum type, const GLvoid *pixels ) PARAMETERS target Specifies the target texture. Must be GL_TEXTURE_2D. level Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image. xoffset Specifies a texel offset in the x direction within the texture array. yoffset Specifies a texel offset in the y direction within the texture array. width Specifies the width of the texture subimage. height Specifies the height of the texture subimage. format Specifies the format of the pixel data. The following symbolic values are accepted: GL_COLOR_INDEX, GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA, GL_ABGR_EXT, GL_LUMINANCE, and GL_LUMINANCE_ALPHA. type Specifies the data type of the pixel data. The following symbolic values are accepted: GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV. pixels Specifies a pointer to the image data in memory. DESCRIPTION Texturing maps a portion of a specified texture image onto each graphical primitive for which texturing is enabled. To enable and disable two- dimensional texturing, call glEnable and glDisable with argument GL_TEXTURE_2D. glTexSubImage2D redefines a contiguous subregion of an existing two- dimensional texture image. The texels referenced by pixels replace the portion of the existing texture array with x indices xoffset and xoffset + width - 1, inclusive, and y indices yoffset and yoffset + height - 1, inclusive. This region may not include any texels outside the range of the texture array as it was originally specified. It is not an error to specify a subtexture with zero width or height, but such a specification has no effect. Normally glTexSubImage2D is synchronous: OpenGL executes a glTexSubImage2D command in the order it is issued in the OpenGL command stream. Calling glEnable with parameter GL_ASYNC_TEX_IMAGE_SGIX causes subsequent glTexSubImage2D commands to be asynchronous as defined by the SGIX_async extension. An asynchronous glTexSubImage2D command samples the OpenGL state vector at the point in the OpenGL command stream where the command is issued, but the results of the command (e.g. availability of texels for use in rasterization) do not happen until some unspecified time in the future. In particular, the order of the asynchronous command relative to other OpenGL commands issued later in the command stream is undefined. An implementation may choose to execute asynchronous commands in parallel with the normal command stream or at some convenient time in the future. Calling glDisable with parameter GL_ASYNC_TEX_IMAGE_SGIX restores the default synchronous behavior for subsequent glTexSubImage2D commands. It does not affect any pending asynchronous glTexImage commands, or wait for their completion. When an asynchronous glTexSubImage2D command is issued, it is associated with the current value of GL_ASYNC_MARKER_SGIX as defined by the SGIX_async extension. A program can determine if an asynchronous glTexSubImage2D command has completed by using the glFinishAsyncSGIX or glPollAsyncSGIX commands. There is a maximum number of asynchronous glTexImage commands that can be outstanding at any one time, defined by the implementation. This value can be queried with glGetIntegerv with argument GL_MAX_ASYNC_TEX_IMAGE_SGIX. NOTES glTexSubImage2D is available only if the GL version is 1.1 or greater. Texturing has no effect in color index mode. glPixelStore and glPixelTransfer modes affect texture images in exactly the way they affect glDrawPixels. Formats GL_BGR, and GL_BGRA and types GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV are available only if the GL version is 1.2 or greater. GL_ABGR_EXT is valid only if the EXT_abgr extension is supported. When the GL_ARB_imaging extension is supported, the RGBA components specified in pixels may be processed by the imaging pipeline. See glTexImage1D for specific details. ERRORS GL_INVALID_ENUM is generated if target is not GL_TEXTURE_2D. GL_INVALID_OPERATION is generated if the texture array has not been defined by a previous glTexImage2D operation. GL_INVALID_VALUE is generated if level is less than 0. GL_INVALID_VALUE may be generated if level is greater than log max, where 2 max is the returned value of GL_MAX_TEXTURE_SIZE. GL_INVALID_VALUE is generated if xoffset < -b, (xoffset + width) > (w - b), yoffset < -b, or (yoffset + height) > (h - b), where w is the GL_TEXTURE_WIDTH, h is the GL_TEXTURE_HEIGHT, and b is the border width of the texture image being modified. Note that w and h include twice the border width. GL_INVALID_VALUE is generated if width or height is less than 0. GL_INVALID_ENUM is generated if format is not an accepted format constant. GL_INVALID_ENUM is generated if type is not a type constant. GL_INVALID_ENUM is generated if type is GL_BITMAP and format is not GL_COLOR_INDEX. GL_INVALID_OPERATION is generated if glTexSubImage2D is executed between the execution of glBegin and the corresponding execution of glEnd. GL_INVALID_OPERATION is generated if type is one of GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, or GL_UNSIGNED_SHORT_5_6_5_REV and format is not GL_RGB. GL_INVALID_OPERATION is generated if type is one of GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, or GL_UNSIGNED_INT_2_10_10_10_REV and format is not GL_RGBA, GL_BGRA or GL_ABGR_EXT. GL_INVALID_OPERATION is generated when the SGIX_subsample extension is supported, and the pixel storage mode GL_UNPACK_SUBSAMPLE_RATE_SGIX is not GL_PIXEL_SUBSAMPLE_4444_SGIX, and width is not a multiple of 2, or format is not a 3 or 4 component format, or type is a packed pixels type. GL_INVALID_OPERATION is generated if GL_ASYNC_TEX_IMAGE_SGIX is enabled and the number of asynchronous glTexImage commands that have been issued but not queried (using glFinishAsyncSGIX or glPollAsyncSGIX) exceeds GL_MAX_ASYNC_TEX_IMAGE_SGIX. ASSOCIATED GETS glGetTexImage glIsEnabled with argument GL_TEXTURE_2D MACHINE DEPENDENCIES The SGIX_async and SGIX_async_pixel extensions are implemented only on Octane2 VPro systems. RealityEngine, RealityEngine2, and VTX systems do not support color matrix transformations on images as they are loaded to or read back from texture memory. RealityEngine, RealityEngine2, and VTX systems do not support convolving images as they are loaded into texture memory. On InfiniteReality systems, there is a performance benefit when the width of the image to be transferred to texture memory is a multiple of 8. Texture borders are not supported on InfiniteReality systems. Applications should use borderless textures and GL_CLAMP_TO_EDGE_SGIS wrap mode. RealityEngine, RealityEngine2, and VTX systems do not support histogram or minmax operations on images as they are being loaded into texture memory. The SGIX_interlace extension is supported only on InfiniteReality systems, on RealityEngine, RealityEngine2, and VTX systems, on Octane2 VPro systems, and on O2 systems. The EXT_packed_pixels extension is not supported on RealityEngine, RealityEngine2, and VTX systems. The SGIX_subsample and SGIX_resample extensions are supported only on Octane2 VPro systems. Applying the GL_PIXEL_SUBSAMPLE_2424_SGIX subsample rate is accelerated for direct immmediate mode transfers when the format is GL_RGB or GL_RGBA, and the type is GL_UNSIGNED_BYTE or GL_UNSIGNED_SHORT. On RealityEngine, RealityEngine2, and VTX systems, glTexSubImage2D and glTexSubImage2DEXT are supported with the following restrictions: 1. Performance is significantly better if the texture subimage X offset, Y offset, width and height are multiples of 32. 2. glTexSubImage2D and glTexSubImage2DEXT may be used only with a texture that was created using glTexImage2D with a NULL texture image. 3. glTexSubImage2D and glTexSubImage2DEXT may not be used with a mipmap texture. Only level 0 is supported. 4. Only the following texel format and type combinations are supported: GL_LUMINANCE and GL_UNSIGNED_BYTE, GL_LUMINANCE and GL_UNSIGNED_SHORT, GL_LUMINANCE_ALPHA and GL_UNSIGNED_BYTE, GL_LUMINANCE_ALPHA and GL_UNSIGNED_SHORT, GL_RGB and GL_UNSIGNED_BYTE and GL_RGBA and GL_UNSIGNED_BYTE. Any other combination of format and type will result in a GL_INVALID_ENUM error. 5. Using glTexSubImage2D or glTexSubImage2DEXT in conjunction with pixel mapping results in a GL_INVALID_OPERATION error (see glPixelTransfer and glPixelMap). 6. glTexSubImage2D and glTexSubImage2DEXT may not be used in display lists or when rendering remotely. 7. GL_INTERLACE_SGIX is not supported (see glEnable). On High Impact and Maximum Impact systems, if the right side of the image to be transferred to texture memory is not the right side of the texture, then its index must be a multiple of 32, where index = xoffset+width. Otherwise it will generate a GL_INVALID_VALUE error. SEE ALSO glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage2D, glCopyTexSubImage3D, glDrawPixels, glPixelStore, glPixelTransfer, glTexEnv, glTexGen, glTexImage1D, glTexImage2D, glTexImage3D, glTexSubImage1D, glTexSubImage3D, glTexParameter, glAsyncMarkerSGIX, glDeleteAsyncMarkersSGIX, glFinishAsyncSGIX, glGenAsyncMarkersSGIX, glIsAsyncMarkerSGIX, glPollAsyncSGIX